RBE3's are interpolation constraint elements, where the motion of a dependent node is defined as the weighted average of the motions of a group of independent nodes.

The dependent degrees of freedom and weighting factors can be specified. RBE3's are typically used to distribute loads applied on the dependent node amongst the selected independent nodes.
Note: The dependent node cannot be directly constrained, as this would lead to a double-dependency for that node.

Create RBE3 Elements

Use the RBE3s tool to create elements.

  1. From the Model ribbon, click the arrow next to the Rigids tool and select RBE3s.
  2. Define the element.
    Option Action
    Type Select a RBE3 element type.
    Calculate dependent node The dependent node is calculated to be at the centroid of previously selected independent nodes. So dependent node selection is made unavailable.
    Dependent node Select one or more dependent nodes.
    Independent node(s) Select the independent node of the rigid element.
    Independent DOF Select degrees of freedom at independent nodes.
    Dependent DOF Select degrees of freedom at dependent nodes.
    Independent WT Weight factor for independent nodes.
  3. Click Create.

Update RBE3 Elements

Use the Entity Editor to update RBE3 elements.

This includes: modifying the independent and dependent node(s) selection, modifying the DOF, where applicable for the solver, and recalculating the independent node location.

Note: To change the element type, see Change Element Type.